Implantable medical devices, such as electrical stimulators or sensors, are used in a variety of therapeutic applications. In some implantable medical devices, an electrical stimulator or sensor delivers electrical pulses to a target tissue site within a patient with the aid of one or more medical leads. The medical leads are coupled to the implantable medical device at one end while the other end carrying electrodes is placed at the target tissue site. The electrodes may be used in stimulating and/or sensing applications.
The ability of an electrode to transfer current is related to its conductivity and its surface area. As electrodes become smaller in size, there is a corresponding reduction in surface area and thus the ability of the electrode to transfer current. Thus, there is a need for an electrode and a medical lead including an electrode that is capable of providing desired current transfer even as the size of the electrode decreases.